The present invention relates generally to communication systems, and more specifically to a method and device for transmitting serial data at very high speeds.
Transferring high speed digital signals between various parts of a computer system, or between systems, is a common requirement. In order to increase bandwidth, parallel data transmission is used wherever possible. However, due to cost, weight, interference (noise), and electrical loading considerations, parallel transmission is not feasible for many systems. In order to simplify the communications problem, data can be transmitted serially. This requires less hardware for the actual communications link. However, parallel data must be converted to serial form for the transmission. The bit rate for the transmission of serial data must be much higher than that required to transmit data in parallel form.
This high bit rate requirement has limited the usefulness of the serial data link in high speed communications systems in the past. However, faster bit rates are becoming available with current technology, and the use of fiber optics as the transmission medium holds the promise of much higher bit rates in the future. Current fiber optic transmission and reception hardware is quite complex, requiring a large number of integrated circuits for each function. Such implementations are not pratical in low cost systems, or in some systems having severe weight and space restrictions, such as on board an aircraft or a satellite.
It would be desirable for a serial data link using fiber optic communications to utilize high bit rate data transmission, and to be realizable in a small number of relatively inexpensive integrated circuits.
Therefore, according to the present invention, a method for communicating high speed serial data includes encoding data with both zero and one insertion, and decoding the received serial data using zero and one deletion. The encoding and decoding functions can be easily implemented on a single integrated circuit for each function, and are capable of transmitting data at very high bit rates.